(a) Field of the Invention
This invention generally relates to a system and method for capturing ferrous objects that are being carried by a flow of material, such as a flow of food waste that is traveling through the intake of a food waste disposal, such as the type commonly used in cafeterias or restaurants and the like. More particularly, but not by way of limitation, to system that and method that uses static focused magnets to pull and retain ferrous items, such as silverware, at a location near the inlet of a waste-food grinding device.
(b) Discussion of Known Art
It is quite common to find a food waste grinder in sinks to help break up and dispose of the food waste through a kitchen's sewer system. A known problem associated with these devices is the accidental introduction of flatware, which is commonly primarily made of a ferrous material, into the device. Flatware that enters the device inevitably results in damage flatware, and may result in damage to the waste grinder as well. Examples of approaches at addressing the problem of accidental introduction of flatware into a sink are found in U.S. Pat. No. 6,626,297 to Dailey and U.S. Pat. No. 4,706,818 to Zutell et al, both of which are incorporated herein in their entirety by reference.
An important problem associated with known devices is that they are not easily added to an existing system. For example, the Dailey device needs to be installed around the inlet of the disposal device, below the sink, which may not present a problem for a new installation, but can be burdensome to install in existing systems. The approach disclosed in the Zutell et al patent may be inserted into the inlet a disposal system, but is likely to result in significant obstruction of the flow, due to the fact that it consists of fixed magnets that extend across the inlet.
Still another device that is used to catch ferrous flatware along a flow is disclosed in U.S. Pat. No. 4,279,744 Antonwitsch, which is also incorporated herein by reference in its entirety. The Antonwitsch device is based on the use of magnets mounted along an axle. The axle is supported by bearings at the ends of the axle. While the movement provided by the use of an axle disclosed by Antonwitsch is of interest, the arrangement of magnets along the axle greatly reduces the efficiency of the device, since it must be mounted at a significant distance from the flow of waste material. Since the strength of a magnetic field of a dipole magnet typically decreases in approximate proportion to the inverse square of the distance from the magnet, it is important to find a solution that places the magnets as close as possible to the flow of waste that may contain flatware. Increasing the distance by two places one at a location where the magnetic field is at one-quarter of its original strength. Accordingly, the Antonwitsch device suffers from the limitation that the support of the magnets results in an inefficient use of the magnetic field.
In my U.S. Pat. No. 6,352,160, incorporated herein by reference in its entirety, I disclose a system that mounts along a trough or similar flow containment device that carries food waste items, and which uses magnets to separate flatware from the flow.
Therefore, a review of known devices reveals that there remains a need for a system that can be used to remove flatware or other ferrous objects from a moving flow of material that is carrying the flatware.
Still further, there remains a need for a system that can be used to modify existing flow based waste carrying systems, without having to modify extensively the existing trough or arrangement used to wash the waste products towards a grinding or disposal system.